Text-driven causal mapping of PET/rPET circularity in Australia: A dynamic factor–network analysis

PET circularity is often evaluated by recovery volumes, although performance ultimately depends on whether recovered material can be converted into quality-assured outputs and absorbed by viable end markets. Yet the mechanisms connecting policy, markets, technology, and stakeholder behavior remain dispersed across heterogeneous evidence. We developed a source-attributed, time-stamped causal-network approach using 750 Australian government, industry and NGO, corporate, and media documents published during 2010–2025. Causal extraction, semantic normalization, sentiment assignment, and graph construction yielded 2794 factor nodes and 1588 unique causal edges. The network was strongly externalized: policy, market, and social factors were more numerous and highly connected than internal technical and operational factors. Persistent barriers combined cost and price volatility, inconsistent recyclate quality, infrastructure gaps, and weak policy implementation. Positive mechanisms clustered around standards and measurement, design for recyclability, operational capacity, and end-market development; their circular value depended on retained material quality and the end use reached. Source attribution revealed systematic framing differences, with media coverage concentrating negative implementation narratives. Temporal and regional analyses indicated a shift from limited attention to rapid expansion and subsequent consolidation, alongside national structural hubs and differentiated state pathways. A full-text academic shadow corpus preserved the broad problem domains but changed their hierarchy: academic evidence foregrounded material and processing mechanisms, whereas the primary corpus foregrounded institutional coordination and market implementation. The contribution is therefore not a universal ranking of Australian interventions, but an auditable framework for identifying how technical feasibility becomes, or fails to become, operational circularity under different institutional conditions.